Menu Item Type can only be product

I'm new with Joomshopping and i can't figure it out:
I put all my products in the system and now i want to build the shop. But i have the next problem: When i choose my menu-item type it stays on 'product'. In the list i can choose shop, basket, user, etc. But when i click on it stays on 'product'.

I tried a older version on a other joomla website (1.5) and it all works. But when i do it on my joomla 1.6 site, it doesn't.

I have no idea what i am doing wrong. Maybe the installation isn't good? Or am i missing something?

I hope someone can help me because i'm going crazy. I already put enough hours in it and i want to keep on using this extension because i thougt it is a great one!